package com.itheima.xixi.controller;

import com.itheima.xixi.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    @Value("${xixi.path}")
    private String basePath;
    //上传文件
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是临时文件，要转存到另外的位置，否则请求完后就会被删除

        //获取原始文件名
        String originalFilename = file.getOriginalFilename();
        //截取后缀名.jpg
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名重复导致覆盖
        String fileName = UUID.randomUUID().toString() + suffix; //拼接字符串
        //创建一个目录文件
        File dir = new File(basePath);
        //判断当前目录是否存在
        if (!dir.exists()){
            dir.mkdir();
        }

        //异常处理
        try{
            //转存到D盘下的photo文件夹中，basePath是映射路径
            file.transferTo(new File(basePath+fileName));

        }catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }

    //文件下载
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        //输入流，通过流读入文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));

            //输出流，通过输出流文件写回浏览器，在浏览器显示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes =new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            outputStream.close();
            fileInputStream.close();

        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}
